Sky News reported Adamson’s exit could be announced by the regulator in the next few days.
Adamson has worked for the FCA, and its predecessor the Financial Services Authority, since 2007 in a variety of roles such as director of major retail groups and senior adviser.
His departure comes as the FCA prepares to release its findings from a probe into the providers of closed-life insurance policies next week.
In March, the FCA briefed the media on the probe, and the subsequent news coverage sending shares of some of the largest insurers spiralling.
In April, law firm Clifford Chance was appointed to lead an inquiry on the disclosure of market-sensitive information and internal communication within the FCA.
However, Sky News reported Adamson’s departure is not connected to the forthcoming report by Clifford Chance, in which he is likely to face criticism.
Adamson was also grilled earlier this year for his decision to approve Paul Flowers as chairman of the Co-operative Bank.
